There is known a method of sorting semiconductor devices according to their electric parameters (cf. SU Inventor's Certificate No. 472,486; Int.Cl..sub.2 H 05 13/02, published in 1975), including the steps of feeding semiconductor devices into a contact mechanism, connecting the contact elements of the contact mechanism to the leads of the semiconductor device, measuring the electric parameters of the semiconductor device, disconnecting the contact elements from the leads of the semiconductor device and delivering the semiconductor device.
In this sorting method the steps or operations are carried out in succession, one by one, without superimposing them in time. The fact reduces the throughput attainable with this known method of sorting semiconductor devices.
The closest prior art of the present invention is the method of sorting semiconductor devices realized in the transistor sorters manufactured by Daymarc Corporation, the USA, Types 1635 and 3235 (cf. Quotation by Digital Processing Corporation, dated May 15, 1977, enclosing the condensed bulletins of Transistor Sorters, Types 1635 and 3235, manufactured by Daymarc Corporation), the method likewise including the steps of feeding semiconductor devices into the probe or contact mechanism, connecting the contact elements of the contact mechanism to the leads of the semiconductor device, measuring the electric parameters of the semiconductor device, disconnecting the contact elements from the leads of the semiconductor device and delivering the semiconductor devices.
The throughput attainable with this method is higher than that attainable with the previously described one, because in the last-mentioned method the steps or operations of feeding the semiconductor devices into the contact mechanism and delivering the semiconductor devices are superimposed in time. However, the throughput attainable with this method is limited by the fact that the majority of its steps or operations are not superimposed in time.
There is known an apparatus for testing and sorting electronic components (cf. the abovecited SU Inventor's Certificate No. 472,786; Int.Cl..sup.2 H 05 K 13/02, published 1975), comprising a conveying rotor with sockets adapted to accommodate the electronic components, a lever mounted for rotary motion coaxially with the rotor, having contact elements on its one arm and followers on its other arm, adapted to engage a cam, and a measuring unit. With the rotor moving, the contact elements connect the electronic components carried in the sockets of the rotor successively to the measuring unit. Upon the completion of the measurement or testing of the component in one socket, the contact elements return toward the successive socket, while the already tested component is directed into the sorting unit. However, this structure would not provide for superimposing the operations in time, since the time required for the return of the contact elements to the successive socket is not superimposed on the time required for carrying out other operations. This fact curbs down the throughput of the apparatus.
There is known an apparatus for performing the method embodied in Sorters, Types 1635 and 3235 manufactured by Daymarc Corporation, the USA, Comprising means for loading semiconductor devices, a contact mechanism or probe with contact elements, electrically connected with a unit for measuring the electric parameters of the semiconductor devices, and a conveying mechanism for delivering the sorted out semiconductor devices into respective receptacles or bins.
However, the design of the said Sorters, Types 1635 and 3235 embodying the abovedescribed method is relatively complicated, and their throughput is limited.